The multi-authored play A Thousand Stars Explode in the Sky dangles the carrot of three of our finest playwrights, David Eldridge, Robert Holman and Simon Stephens, collaborating. It also offers a tantalising prospect to collectors of theatrical memorabilia. When the trio were working on the play – a tremendously complicated on-and-off process that took seven years – they used all sorts of different methods. Initially, they wrote scenes very quickly off the tops of their heads. This included writing a scene together on rolls of wallpaper. Holman still has one of these scrolls in his possession. "I kept it as my pension," says the playwright. "I'm relying on David and Simon to become mega-famous so I can live on the proceeds."

The play, which opens tonight at the Lyric Hammersmith in London, is about brothers ranging in age from 15 to 54. It also tells of the end of the universe. "We wanted it to be epic, but it's far bigger than we dared anticipate," says Eldridge.

As the collaboration progressed, it saw the writers working "towards a play where we were all on every page, if not in every line," says Eldridge.

The playwrights have even started to forget who wrote what. "The author is the three of us, and I'd challenge anyone to separate our voices," he adds.